Drill feeding mechanism



May 16, 1933. M c. HUFFMAN DRILL FEEDING MEGHANISM Filed DSG. 14, 1929 QN NN Patented May 16, 1933 UNITED STATES'PATENT oFFlcE MERV'IN C.` HUFFMAN, OF CLAREMONT, NEW HAMPSHIRE, ASSIGNOB TO SULLVAN MACHINERY COMPANY, A CORPORATION F MASSACHUSETTS DRILL FEEIOING MECHAN'ISM Application filed December 14, 1929. Serial No. 414,134.

This invention relates generally to pressure fiuid operated tools and in the specific embodiment illustrated herein it has particular significance in the field of drilling and is especially related to the means for feeding a drill in an improved manner.

In drilling mechanisms, particularly of the mounted pneumatic hammer type, such as a drifter, it is desirable to feed the drill a considerable distance at one setting of the machine.v This permits using a drill steel of considerable length, and thus avoids the necessity of inserting steels of successively greater length as the depth of the hole in-v creases, this procedure being the one usually followed with drills having a relatively short feed.

One object of my invention is to provide an improved feeding mechanism for a mounted drill, while a further and more specific object of the invention is to provide an improved extensible feeding arrangement so disposed with respect to and in association with the mounted drill as to provide an arrangement which is' extremely compact, rugged, economical to manufacture and easy to assemble and disassemble and operate.

While other objects and advantages might be mentioned at this point, yet it is believed that the same will be readily apparent from the following description of the accompanying drawing which illustrates, for simplicity, only one embodiment that the invention may take, and in which:

Fig.- 1 is a side elevation of a drifter type drill with part of the feeding means being shown in section.

Fig. 2 is an enlarged view of the machine with'the feeding mechanism shown in col- 4 lapsed condition, which is the most forward feeding position attainable, the controlling valve being set so as to return the drill and feeding mechanism to the starting position.

, Fig. 3 is a transverse section on line 3-3 of Fig. 2.

Fig. 4 is an enlarged sectional view of the feeding control valve in the position for feeding the drill forwardly. y

While my invention is illustrated with a drifter type of percussive tool it will, of course, be understood thatthe various principles and structural features disclosed herein may be employed with other similar mechanisms, but, as will be seen from the following description, the invention is peculiarly adapted to the feeding of a drifter.

The machine comprises in its specific embodiment a shell l of exceptional length, having a central support 2 which is normally clamped upon suitable supporting elements well known in the art. The percussive motor 3 is guided in suitable lateral guideways 4 formed near the upper edges of the shell with the motor disposed above the hollow por,- tion of the shell. The motor may be of any usual type which herein is merely diagrammatically illustrated, but it will, of course, be understood the same has a piston operated by air pressure to impart a series of blows to a drill steel 6. This steel is shown of considerable length so as to permit my im roved feeding means to effect a continuous eed of substantial distance without requiring a change of steels. To effect this feeding the rear head 7 of the percussive motor extends downwardly between the guideways 4 and has secured at its lower end a piston rod 8 which carries a piston 9 at-its forward end, this piston in turn being mounted in a combined cylinder and piston rod 10 which has at its forward end an enlarged head 11 forming a piston slidable within the outermost cylinder 12. It is thus seen that there are a plurality of telescopic cylinders and pistons, all disposed within the hollow of the shell at the forward end thereof, it being noted in particular that the outer cylinder is formed by the wall of the shell. The inner ends of the cylinders are provided with any suitable packing generally indicated at 13 while the 90 usual manner with an axial fluid pressure inlet 15, from which fluid pressure is supplied through a port 16 to passages 17 and 18 to the right end of the piston 9, fluid in turn passing through a port 19 formed in the otherwise closed end of piston 11, thereby causthereb lside o piston 9 to feed the saine forwardly.

ing a fluid pressure force to be exerted on piston 11 so as to move the same rearwardly toward the starting position for a drilling operation. Piston-ll will move rearwardly the length of cylinder 12 whereupon the pressure acting in the end of the inner cylinder 10 will continue the rearward movelnent of the drill for the length of the inner cylinder 10. During lengthening of the feeding mechanism the left end of each of the 'inner and outer cylinders are vented to atmosphere by a port 20, passages 21, 22, groove 23 formed in the periphery of control valve 14, and pas-l sage or a port 24.

When it is desired to feed the steel for.- wardly the control valve 14 is turned ,substantially 45 to the position shown in Fig. 4, wherein it will be seen that the fluid pressure supply port 16 registers with passage 22, supplying pressure fluid to the left When it approaches the forward end of the inner cylinder 10, port 20 will Abe uncovered to admit fluid to the outer cylinder 12, whereupon the piston 11 will then feed forwardly to complete the feeding stroke. During this operation the right ends of the cylinders are vented to atmosphere by Way of a groove 25 and port 26, associated with the control valve.

It is thus seen that I have provided adrifter type drill having an extremely compact arrangement adapted to effect feeding for a distance materially greater than the length of the feeding mechanism when in its collapsed form and at the same time by the location of the plurality of cylinders-within the shell ofthe drifter, many advantages are obtained, such for instance as full protection of the mechanism. Also by having the feeding mechanism disposed at the front end of the shell and having the percussive motor connected at the rear point of the feeding mechanism there is the advantage thatas the hole is drilled weight will be accumulated on the front end of the drill, thereby tending to provide a better counter-balance for the percussive action of the motor and thus tend to effect a dynamic balance of the machine as a whole, whereas on the other hand during the setting-up operation of the machine and with the feed cylinders extended the machine has a tendency to be statically balanced 'about the central clamping member 2 which facilitates handling by the operator. It is also seen that by having the cylinder located poses of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

lVhat I claimasnew and desire to secure by Letters Patent is:

1. A drifter type of drilling mechanism comprising, in combination, a guide shell, a rock drill slidably guided on said shell, means for feeding said drill relativeA to said shell comprising a pneumatic feeding motor contained Within said shell land including a feed cylinder formed integral with the shell and forming a part of the shell structure, a feed piston reciprocably mounted in said cylinder and having a hollow piston rod forming a second feed cylinder, a feed piston reciprocably mounted in said second feed cylinder and having a piston rod, a connection between said last mentioned piston rod and the rock drill, and means for sup lying pressure fluid to said cylinders to ed cation of said pistons including parallel passages formed in said connection and communicating parallel passages formed in said last mentioned piston rod, said last mentioned passages communicating with said second cylinder at opposite sides of said last mentioned feed piston.

2. drifter type of drilling mechanism comprising, in combination, a guide shell, a rock drill slidably guided on said shell, means for feeding said drill relative to said shell comprisin a pneumatic feeding motor contained wit in said shell and including a feed cylinder formed integral'with the shell and forming a part of the shell structure, a feed piston reciprocabl mounted in said cylinder and having a hol ow piston rod forming a second feed cylinder, a feed piston reciprocably mounted in said second feed cylinder and having a piston rod, a connection between said last mentioned piston rod and the rock drill, and means for sup lying pressure fluid to said cylinders to effect reciprocation of said pistons including parallel passages formed in said connection and communicating parallel passages formed in said last mentioned piston rod, said last mentioned passages communicating with said second cylinder at opposite sides of said last mentioned feed piston, and a passage traversing the wall of said second cylinder for supplying fluid from a passage insaid last mentioned piston rod through said second cylinect reci proder into said first cylinder to effect movement of said first mentioned piston in one direction.

3. A drifter type of drilling mechanism comprising, in combination, a lguide shell, a rock drill slidably guided on said shell, means for feeding said drill relative to said shell comprising a pneumatic feeding motor contained within said shell and including a feed cylinder formed integral with the shell and forming a part of the shell structure, a .feed piston reciprocably mounted in said cylinder and having a hollow piston rod forming a second feed cylinder, a feed (piston reciprocably mounted in said secon feed cylinder and having a piston rod, a connection between said last mentioned piston rod and the rock drill, and means for supplying pressure fluid to said cylinders to effect reciprocation of said pistons including parallel passages formed in said connection and communicating parallel passages formed in said last men- 'tioned piston rod, said last mentioned passages communicating with -said second cylinder at opposite sides of said last mentioned feed piston, and a valve carried by said drill for alternatively connecting said parallel passages with a source of fluid supply and. exhaust. u

4. A drifter type of drilling mechanism comprising, in combination, a guide shell, a rock drill slidably guided on -said shell, means for feeding said drill relative to said shell comprising a pneumatic feeding motor contained within said shell and including a feed cylinder formed integral with the shell and forming a part of the shell structure, a feed piston reciprocably mounted in said cylinder and having a hollow piston rod forming a second feed cylinder, a feed piston reciprocably mounted in said second feed c'ylinder and having a piston rod, a connection between said last mentioned piston rod and the rock drill, and means for supplying pressure fluid to said cylinders to effect reciprocation of said pistons including parallel passages formed in said connection and, communicating parallel passages formedin said last-mentioned piston rod, said last mentioned passages communicating with said second cylinder at opposite sides of said last mentioned feed piston, a passage traversing the wall of said second cylinder for supplying fluid from a passage in said last mentioned piston rod through said second cylinder into said first cylinder at one side of said first mentioned piston to effect movement of said first mentioned piston in one direction, and a passage traversing the end wall of said first mentioned piston for conducting fluid from the other of said parallel passages to said first mentioned cylinder at the'other i side of said first mentioned piston to effect movement of said first mentioned piston in the opposite direction.

l5. A- drifter type of drillingcmechanism comprising, in combination, .a guide shell, a rock drill slidably guided on said' shell, means for feeding said rock drill relative to said shell comprising a pneumatic feeding motor contained within 'said shell and including a feed cylinder formedintegral with the forward portion of the shell and'forming a part of the shell structure, a feed piston reciprocably mounted in said cylinder and having -a rearwardly extending hollow piston rod forming a second feed cylinder, a feed piston reciprocably mounted in said second cylinder and having a rearwardly extending piston rod, a connection between the rear end of said last mentioned piston rod and the rear end of the rock drill, and means for supplying pressure fluid to said feed cylinders to effect reciprocation of said pistons including passages formed in said connection and said last mentioned piston rod and a valve carried by the rear portion of the rock drill adjacent said connection for controlling such fluid supply.

6. A reversible pneumatic feeding motor for feeding a rock drill including a feed cylinder, a feed piston reciprocably mounted in said feed cylinder and having a hollow piston rod forming a se-cond cylinder, a feed piston reciprocably mounted in said second cylinder and having a piston rod, and means for supplying pressure fluid to said cylinders to effect feed selectively in opposite directions including passages formed in said lastnientioned piston rod and communicating with the second cylinder at opposite sides of the last mentioned feed piston.

7. A reversible pneumatic feeding motor for feeding a rock drill including a feed cylinder, a feed piston reciprocably mounted in said feed cylinder and having a hollow piston rod forming a second cylinder, a feed piston reciprocably mounted in said second cylinder and having a piston rod, and means for supplying pressure fluid to said cylinders to effect feed selectively in opposite directions including passages formed in said last mentioned piston rod and communicating with the second cylinder at opposite sides of the last mentioned feed piston, and a passage traversing the wall of the second cylinder for supplying fluid from one of said passages to said first mentioned cylinder.

8. A reversible pneumatic feeding motor for feeding a rock drill including a feed cylinder, a feed piston reciprocably mounted in said feed cylinder and having a hollow piston rod forming a second cylinder, a second feed piston reciprocably mounted in said second cylinder and having a piston rod, and

means for supplying pressure fluid to saidl cylinders to effect feed selectively in opposite directions including passages formed in said last mentioned piston rod and communicating with the sec-ond cylinder at opposite sides of the last mentioned feed piston, a passage traversing the wall of the second cylinder for supplying fuid from one of said passages to said first mentioned cylinder at one side of the first mentioned piston to effect movement l ofthe latter in one direction, and a passage connectin the other passage in the second mentione piston rod with the first mentioned feed cylinder at the opposite side of said first mentioned piston to effect movement of the latter 1n the opposlte dlrection.

In testimony whereof I 'aix my signature.

MERVIN C. HUFFMAN. 

